After owning the Rebel 500 and hanging out on this forum for a couple of years, I HAD to get a full frame camera. When I bought my 5Dii a few years ago, I sold the T1i and EF-s lens. It wasn't long before I realized the extra weight of my new set-up and I debated for over a year about selling and going lighter. And I went through a few small cameras, looking for a quality P&S and ending up with the EOS M.
A year ago, I did sell the 5Dii and almost returned to crop (70D); but at the last minute, a killer deal sold me on the 6D and 24mm-105mm. And I am very happy that I went with the 6D, it is an outstanding camera. Yet I was still longing for a smaller, quick camera. I gave up using the EOS M, as I didn't like shooting with the LCD screen at all, finding it almost impossible in the bright sun. Recently I sold it and purchased the SL1.
I feel like I have come "full circle", gotten over the gear envy syndrome and no longer feel an urge to upgrade. I am very happy with the SL1, the capabilities, the size, just everything about it. But I am keeping the 6D for the "good stuff". I think both will find a happy home with me.
This weekend I am taking out the 6D with the 100-400mm and the SL1 with the 55-250 STM and see how they hold up against each other in my birding, wildlife shooting.
So in answer to your question, I have full frame yet returned to crop body as well.